Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2013

Defined Benefit Pension Plans [Member]

Defined Benefit Plan Disclosure [Line Items]

Components Of Net Periodic Benefit Expense (Income)

	Qualified Pension Plans
	Three Months Ended September 30,						Nine Months Ended September 30,
(Dollars in thousands)	2013			2012			2013			2012
Interest cost on benefit obligation	$	17,506		$	17,542		$	52,517		$	52,626
Expected return on plan assets	(22,831		)	(21,102		)	(68,493		)	(63,308		)
Amortization of actuarial loss	4,568			4,858			13,704			14,574
Amortization of prior-service costs	418			4			1,253			11
Net periodic benefit expense (income)	$	(339	)	$	1,302		$	(1,019	)	$	3,903
	Non-Qualified Pension Plans
	Three Months Ended September 30,						Nine Months Ended September 30,
(Dollars in thousands)	2013			2012			2013			2012
Interest cost on benefit obligation	$	803		$	860		$	2,410		$	2,579
Amortization of actuarial loss	280			240			839			763
Amortization of prior-service costs	1			—			4			—
Net periodic benefit expense	$	1,084		$	1,100		$	3,253		$	3,342

Postretirement Medical Plan [Member]

Defined Benefit Plan Disclosure [Line Items]

Components Of Net Periodic Benefit Expense (Income)

	Three Months Ended September 30,						Nine Months Ended September 30,
(Dollars in thousands)	2013			2012			2013			2012
Service cost	$	370		$	419		$	1,112		$	1,259
Interest cost on benefit obligation	869			1,080			2,608			3,239
Amortization of prior-service credit	(263		)	(302		)	(789		)	(905		)
Net periodic benefit expense	$	976		$	1,197		$	2,931		$	3,593